Cell III

Question 1

What is the supportive structure of an animal cell

Answer 1

– Composed of microtubules, intermediate filaments, and microfilaments

Question 2

What is the supportive structure of a plant cell

Answer 2

– Composed of microtubules and microfilaments

Question 3

What is polymerization?

Answer 3

• Assembly of monomers to extend the length of the
  filament
• Monomers added to the + end

Question 4

What is depolymerization?

Answer 4

• Disassemblyofthefilament
  -Monomers removed from the +end

Question 5

Three major cytoskeletal filaments?

Answer 5

• microtubule
• intermediate filament
• microfilament

Question 6

two types of motor proteins move along microtubules

Answer 6

• kinesin: away from centrosome
• dynein: towards the centrosome

Question 7

Eukaryotic flagella

Answer 7

– Consist of several microtubules
– Move the cell by undulating—they whip back + forth
– Are surrounded by the plasma membrane

Question 8

cilia

Answer 8

– Closely related to eukaryotic flagella
– Short, hairlike projections
– Cells generally have just one or two flagella – Some cells have many cilia

Question 9

what is actin filaments AKA microfilaments

Answer 9

– Formed by polymerization of individual actin molecules into long strands
– Two strands coil around each other
– Grouped together into long bundles or dense networks – Usually found just inside the Plasma membrane

Question 10

what is cell crawling:

Answer 10

• caused by actin filaments growing in one direction, moving the cell

Question 11

types of movement caused by actin-myosin interaction

Answer 11

1. cell crawling
2. cell division in animals
3. cytoplasmic streaming in plants

Question 12

intermediate filaments

Answer 12

– Are defined by size rather than composition
– Many types exist, each consisting of a different protein – Provide structural support for the cell
– Are not involved in movement